Process control systems, like those used in chemical, petroleum or other processes, typically include one or more process controllers communicatively coupled to one or more field devices via analog, digital or combined analog/digital buses. The field devices, which may be, for example, valves, valve positioners, switches and transmitters (e.g., temperature, pressure and flow rate sensors), perform process control functions within the process such as opening or closing valves and measuring process control parameters. The process controllers receive signals indicative of process measurements made by the field devices and then process this information to generate control signals to implement control routines, to make other process control decisions, and to initiate process control system alarms.
Information from the field devices and/or the controller is usually made available over a data highway or communication network to one or more other hardware devices, such as operator workstations, personal computers, data historians, report generators, centralized databases, etc. Such devices typically run a ‘top level’ process control system software application that enables operators and/or engineers to perform any of a variety of functions with respect to the processes of a process control system and interact with the various controllers, field devices, and other components within the process control system. In addition to control system software applications to control the operation of a process control system, operators and/or engineers may also use asset management software applications and/or other software applications to set up, configure, maintain, and/or test the reliability of components and devices within the process control system whether or not the associated process is actually in operation. These various ‘top level’ software applications are collectively referred to herein as process management software applications.
In addition to the ‘top level’ process management software applications, many of the individual controllers, field devices and/or other process control system components have associated software applications that interact with the process management software applications. However, the controllers, field devices, and/or other components in a process control system may be produced by any number of different manufacturers. Accordingly, each manufacturer may provide different hardware devices, each with corresponding software that is different from the hardware and software of other manufacturers. Further, the developers of the process management software applications may be associated with another entity. As a result, many manufacturers and software developers in the process control system industry create hardware and software that comport with standardized application interfacing frameworks to enable interaction between the different software applications and process hardware within a process control system.
A typical application interfacing framework used within the process control system industry is based on object linking and embedding (OLE), component object model (COM), and distributed component object model (DCOM) technologies developed by Microsoft®, as well as later generations of the technology including COM+ and .NET. At a general level, these application interfacing frameworks provide a common structure to interface components/objects of Windows-based software applications.
A particular implementation of these component based interfacing frameworks within the process management industry is known as field device tool (FDT) technology. FDT technology defines standards for the communication and configuration interface between all field devices and their host(s) within a process control system setting. FDT technology involves two main components: (1) an FDT Frame application and (2) a Device Type Manager (DTM). An FDT Frame application is a host application, such as a ‘top level’ process management software application, that may communicate and/or interact with any of the DTMs within a process control system based on the standardized interfacing framework of FDT technology.
A DTM is a software package associated with a particular field device or other process control system equipment containing all the device-specific data, functions and management rules, as well as user interface elements for an operator and/or engineer to configure, operate, and/or maintain the device via the FDT Frame application. Furthermore, some DTMs known as CommDTMs are developed specifically for communication equipment (e.g., gateways, multiplexers, etc.) to enable the conversion of data from one protocol to another (e.g., Ethernet, HART, PROFIBUS, etc.). Accordingly, FDT technology enables the seamless integration of devices from any manufacturer that complies with the FDT framework over one or multiple fieldbus protocols via a single user interface (i.e., the FDT Frame application). Another implementation of the component based interfacing frameworks described above is known as field device interface or field device integration (FDI) that builds upon FDT technology. In particular, FDI technology takes FDT technology and incorporates standards known in the process industry regarding device description (DD) technology to further enable the interfacing and communication of field devices within a process control system setting.